What the Bible says about Harmony of the Gospels
(From Forerunner Commentary)

Matthew 8:28-34 Jesus stayed in Gadara only for a few hours, but during that time, He came across two demon-possessed men (Matthew 8:28-34; Mark 5:1-20; Luke 8:26-40). Although Matthew's account mentions two men, and Mark and Luke record only one, no contradiction exists between them. The simple explanation is that one of the men, acting as their spokesman, was more prominent and aggressive, and thus more noticeable than the other. Perhaps Matthew, directing his gospel toward Jews, emphasized their number, knowing the legal weight of two witnesses (Deuteronomy 17:6; 19:15). Martin G. Collins The Miracles of Jesus Christ: Two Demon-Possessed Men Healed (Part One) Related Topics: Alleged Contradiction in Scripture | Contradiction in Scripture, Alleged | Exorcism of the demons in Gadara | Legal weight of two witnesses | Miracles of Jesus Christ: Exorcism of Demons | Two Witnesses